Search results for "computer vision"
showing 10 items of 2353 documents
Digital Acquisition and Processing of Video Angiocardiograms
1986
Angiocardiographic diagnosis is still mainly based on the visual assessment of radiographic projection images recorded on photographic film. Considerable amounts of contrast material have to be selectively injected into the circulation in order to make the regions of diagnostic relevance visible in the superposition of the shadows of tissue and bone structures displayed in these transmission images. In addition, selective angiocardiography requires exact positioning of the catheter, a time-consuming procedure which is not without risk. The processing of the angiographie films obtained is difficult to maintain at a constant high quality level, and this introduces an disadvantageous delay bet…
Real and simulated endoscopy of neurosurgical approaches in an anatomical model
1997
Endoscopy simulation is a new visualisation technique which can be used to visualise patient anatomy as seen through endoscopes. In the following, we describe the application of simulated endoscopy to neurosurgical endoscopic approaches. We assess different aspects of virtual images and their influence on the final result, as judged by clinicians. One of these aspects is the projective geometry which is used to render the 3D images. Rendering using stereographic projection leads to more realistic endoscopic views than perspective projection.
Study of CT/MRI mutual information based registration applied in brachytherapy
2016
The present work aims to include magnetic resonance imaging (MRI) in a Medical Image-based Graphical platfOrm - Brachytherapy module (AMIGOBrachy) which coupled to the Monte Carlo N-Particle (MCNP6) code allows absorbed dose calculations. Computed tomography (CT) and MRI images were registered using mutual information algorithms to improve tissue segmentation potentially leading to a more accurate treatment planning system.
NIR tracking assists sports medicine in junior basketball training
2011
We recorded eye movements of eight elite junior basketball players. We hypothesized that a more stable gaze is correlated to a better shot rate. Upon preliminary testing we invited male juniors whose eyes could be reliably tracked in a game situation. To these ends, we used a head-mounted video-based eye tracker. The participants had no record of ocular or other health issues. No significant differences were found between shots made with and without the tracker cap, Paired samples t-test yielded p= .130 for the far and p=.900 > .050 for the middle range shots.The players made 40 shots from common far and middle range locations, 5 and 4 meters respectively for aged 14 years As expected, a st…
Ocular counterrolling. Some practical considerations of a new evaluation method for diagnostic purposes.
1986
Ocular counterrolling (OCR) data taken from the literature (12 publications) were used to test the best fit (least-square fit) of these measurements with respect to three mathematical models: a sine relation between OCR and the lateral tilt stimulus, a complex cosine-square relation, and a logarithmic relation between OCR gain and tilt. The latter proved to be the best fitting function. On the basis of this model, we attempted to define a physiological transfer function between OCR gain and tilt, which could serve as a reference of normal population, assuming healthy subjects for the investigations applied. Comparison of this physiological range with pathological data demonstrated marked di…
The effect of concomitant benzodiazepine use on neurocognition in stable, long-term patients with bipolar disorder
2020
Objective: Neurocognitive dysfunction is a common feature of bipolar disorder even in euthymia, and psychopharmacological treatment could have an effect on cognition. Long-term prescription of benzodiazepines in bipolar disorder is a common practice, and their effect on neurocognition has not been well studied in this population. The aim of this study was to evaluate the impact of concomitant benzodiazepine long-term use on neurocognitive function in stable euthymic bipolar disorder patients. Methods: Seventy-three euthymic bipolar disorder outpatients and 40 healthy individuals were assessed using a neurocognitive battery. Patients were classified in two groups according to the presence of…
Interreader Reliability of LI-RADS Version 2014 Algorithm and Imaging Features for Diagnosis of Hepatocellular Carcinoma: A Large International Multi…
2017
Purpose To determine in a large multicenter multireader setting the interreader reliability of Liver Imaging Reporting and Data System (LI-RADS) version 2014 categories, the major imaging features seen with computed tomography (CT) and magnetic resonance (MR) imaging, and the potential effect of reader demographics on agreement with a preselected nonconsecutive image set. Materials and Methods Institutional review board approval was obtained, and patient consent was waived for this retrospective study. Ten image sets, comprising 38-40 unique studies (equal number of CT and MR imaging studies, uniformly distributed LI-RADS categories), were randomly allocated to readers. Images were acquired…
Primary ciliary dyskinesia assessment by means of optical flow analysis of phase-contrast microscopy images
2014
Primary ciliary dyskinesia implies cilia with defective or total absence of motility, which may result in sinusitis, chronic bronchitis, bronchiectasis and male infertility. Diagnosis can be difficult and is based on an abnormal ciliary beat frequency (CBF) and beat pattern. In this paper, we present a method to determine CBF of isolated cells through the analysis of phase-contrast microscopy images, estimating cilia motion by means of an optical flow algorithm. After having analyzed 28 image sequences (14 with a normal beat pattern and 14 with a dyskinetic pattern), the normal group presented a CBF of 5.2 +/- 1.6 Hz, while the dyskinetic patients presented a 1.9 +/- 0.9 Hz CBF. The cutoff …
Diagnostic of craniofacial asymmetry : literature review
2009
Facial asymmetry is a common feature in many syndromes, and requires surgery as the only valid treatment option. Routine diagnostic methods (frontal RX, panoramic RX and submentovertex RX) have serious limitations mainly due to the transfer from a three dimensional image to a two dimensional plane. The feasibility of such methods is poorly supported due to inherent projection errors (image magnification, cranial rotation) and identification errors (image quality, precision and reproducibility). The use of computer tomographies represents a substantial improvement in the sense of skeletal and soft tissue structures? reproduction precision. The interpretation of this new data source makes evi…
Snapshot multi-spectral-line imaging for applications in dermatology and forensics
2019
Performance of multi-spectral imaging critically depends on image acquisition time and working spectral bandwidths. Ultimate performance can be achieved if a set of monochromatic (single-wavelength) spectral images is obtained by a single snapshot - a technique provisionally called “snapshot multi-spectral-line imaging” or SMSLI. The SMSLI principle and the developed prototype devices for 3, 4 and 5 spectral line snapshot imaging are described. Two potential practical applications of SMSLI are discussed – for fast mapping of the main in-vivo skin chromophores and for detection of counterfeit banknotes and documents.